Blackwood
Blackwood is a slam-seeking convention for asking aces. It is used to avoid bidding slam contracts when two aces are missing for a small slam or an ace is missing for grand slam. Typically it is invoked with a bid of 4NT when a suit fit has already been identified. More generally, any jump bid of is Blackwood unless it follows directly a natural notrump bid by partner. There are, of course, exceptions. Blackwood is one of the two most-widely used conventions in the world and is taught to beginners at the very beginning (the other one is Stayman), though many players misuse it. The purpose of Blackwood is to avoid bad slams (i.e. slams missing two aces), but not seeking possible slams holding insufficient strength. Therefore, it is wrong to use Blackwood with a void (voidwood may be used instead). Standard Blackwood When Blackwood is on, a bid invokes it: * = 0 or 4 aces * = 1 ace * = 2 aces * = 3 aces Note that the response to the asking may be beyond the point of no return for a small slam. Conventions designed to deal with this are Gerber and Kickback. King asking If all the aces are located, the original bidder may ask for kings with . The responses are then * = 0 or 4 kings * = 1 king * = 2 kings * = 3 kings Note that the bid guarantees all aces are in the partnership, therefore, the responder may directly bid a grand slam if he certain that it is going to make with all aces. Examples * - is Blackwood. * opening may be Blackwood. * - is a quantitative slam invite and is not Blackwood. Variations Variations on the responses Responses with a useful void In addition to the standard responses above, the following non-standard responses show a side void: * : even number of aces with a void (in case of 0 aces and the opener has not shown a strong hand yet, it is possible to just return to the agreed trump suit without showing the void); * 6 of a suit below the agreed trump suit: odd number of aces with the named void; * 6 of the agreed trump suit: odd number of aces with a void above the trump suit. Key card Blackwood When using key card Blackwood, there are five key cards instead of four aces in total: four aces and the trump king. After the asking bid: * shows 0 or 4 key cards; * shows 1 or 5; * shows 2; * shows 3. It is now mostly deprecated and replaced by the method below. Roman key card Blackwood Roman key card Blackwood (RKCB) is similar to above, with 5 key cards, but with the following responses. After the asking bid, * shows 0 or 3 key cards (1 or 4 in the 1430 version); * shows 1 or 4 key cards (0 or 3 in the 1430 version); * shows 2 or 5 key cards, without the trump queen; * shows 2 or 5 key cards, with the trump queen. In general, is used for king asking. However, the non-trump bid after the response may have different uses, either for asking the trump queen, or to sign off at . Some reverse the and response. This further variant is called 1430 while the normal version is called 0314 or 3014. When Gerber is used as the asking bid after NT, there is no such thing called the trump queen, therefore, the higher two responses have some other meaning: * : 0 or 3 aces * : 1 or 4 aces * : 2 aces * : 2 aces Details on which 2 aces are shown by or responses need further partnership agreement to define. Six-ace Roman key card Blackwood Six-ace Roman key card Blackwood, abbreviated six-ace Blackwood, six-key-card Blackwood or 6A-RKCB, is used when there are two potential trump suits. It is similar to RKCB above, but with 6 key cards (4 aces, 2 kings) and 2 queens: * shows 0 or 3 key cards (1 or 4 in the 1430 version); * shows 1 or 4 key cards (0 or 3 in the 1430 version); * , , shows 2 or 5 key cards with various queens, details by partnership agreement. Variations on the asking bid As using Blackwood over a minor suit can easily get the auction too high, some other asking bids have been developed to let the partnership sign off at game. Responses are counted in steps, therefore * in normal Blackwood (or any variation on the response) becomes 1 step above the asking bid; * becomes 2 steps above; * becomes 3 steps above; * becomes 4 steps above. Baby Blackwood A jump to over a 1-level opening is Blackwood. The responses are the same as normal Blackwood, but a level lower. Exclusion Blackwood (or voidwood) When a suit is agreed, a jump to the 4 or 5 level of the agreed suit is the asking bid and shows a void in the bid suit. Therefore, the void ace or the king is not counted in the response, e.g. * - - is voidwood with void: ** shows 0 aces; ** shows 1 ace; ** shows 2 aces; ** shows 3 aces. Then asks for kings. It is possible to combine Roman key card Blackwood with voidwood, in which the responses show keycards except the void ace. Kickback When a suit is agreed, a step above 4 of the agreed suit is the asking bid, i.e. * is Blackwood for NT (Gerber is in fact a special case of Kickback). * is Blackwood for . * is Blackwood for . * is Blackwood for . * is Blackwood for s. It is possible to combine kickback and voidwood together by switching with the suit above the agreed trump suit. The king asking bid is a step above 5 of the agreed suit. Redwood is the same as kickback, but applies to agreed minor only. Its name comes from the fact that (Kickback for s) and (Kickback for s) is a red suit bid. Gerber Gerber is usually used after or . is the asking bid for Gerber and is the king asking bid. Minorwood A non-competitive 4-level raise after a minor suit fit has been found is the asking bid, e.g. * - - is Blackwood for : ** shows 0 or 4 aces; ** shows 1 ace; ** shows 2 aces; ** shows 3 aces. The king asking bid is usually a step above 5 of the agreed suit, since 5 of the agreed suit is always a sign off. In the above example, asks for kings. Interference There are some methods designed to handle interference after the asking bid: DOPI DOPI (and ROPI) is a convention (and a mnemonic) for dealing with interference after a Blackwood 4NT or other ace-asking call. It stands for "(Re)Double-zero-pass-one". In the event of a double, or an overcall below the response showing two aces, then this convention is in effect. Thus, * Double (or redouble) shows zero (or four) aces * Pass shows one ace * One step shows two aces * Two steps shows three aces If the overcall is at or beyond the bid for two aces, DEPO is used instead. DEPO DEPO is a convention (and a mnemonic) for dealing with overcalls after a Blackwood 4NT or other ace-asking call. It stands for "Double-even-pass-odd", and is a generalization of DOPI for when the overcall is too high. If the overcall is at or above the response showing two aces, then this convention is in effect. Thus, * Double shows zero, two, or four aces. * Pass shows one or three aces. External Links * Blackwood Convention on Bridge Guys * Blackwood and Variations on Bridge Guys * Pattaya Bridge Club: Blackwood or Gerber? Category:Bridge World Standard Category:Blackwood Category:Standard American Yellow Card